$key = md5( $_SERVER['HTTP_USER_AGENT'] );

	$response = get_site_transient( 'browser_' . $key );
	if ( false === $response ) {
		// include an unmodified $wp_version
		include( ABSPATH . WPINC . '/version.php' );

		$url     = 'http://api.wordpress.org/core/browse-happy/1.1/';
		$options = array(
			'body'       => array( 'useragent' => $_SERVER['HTTP_USER_AGENT'] ),
			'user-agent' => 'WordPress/' . $wp_version . '; ' . home_url( '/' ),
		);

		if ( wp_http_supports( array( 'ssl' ) ) ) {
			$url = set_url_scheme( $url, 'https' );
		}

		$response = wp_remote_post( $url, $options );

		if ( is_wp_error( $response ) || 200 != wp_remote_retrieve_response_code( $response ) ) {
			return false;
		}

		/**
		 * Response should be an array with:
		 *  'platform' - string - A user-friendly platform name, if it can be determined
		 *  'name' - string - A user-friendly browser name
		 *  'version' - string - The version of the browser the user is using
		 *  'current_version' - string - The most recent version of the browser
		 *  'upgrade' - boolean - Whether the browser needs an upgrade
		 *  'insecure' - boolean - Whether the browser is deemed insecure
		 *  'update_url' - string - The url to visit to upgrade
		 *  'img_src' - string - An image representing the browser
		 *  'img_src_ssl' - string - An image (over SSL) representing the browser
		 */
		$response = json_decode( wp_remote_retrieve_body( $response ), true );

		if ( ! is_array( $response ) ) {
			return false;
		}

		set_site_transient( 'browser_' . $key, $response, WEEK_IN_SECONDS );
	}

	return $response;
}

/**
 * Displays the PHP update nag.
 *
 * @since 5.1.0
 */
function wp_dashboard_php_nag() {
	$response = wp_check_php_version();

	if ( ! $response ) {
		return;
	}

	if ( isset( $response['is_secure'] ) && ! $response['is_secure'] ) {
		$msg = __( 'WordPress has detected that your site is running on an insecure version of PHP.' );
	} else {
		$msg = __( 'WordPress has detected that your site is running on an outdated version of PHP.' );
	}

	?>
	<p><?php echo $msg; ?></p>

	<h3><?php _e( 'What is PHP and how does it affect my site?' ); ?></h3>
	<p><?php _e( 'PHP is the programming language we use to build and maintain WordPress. Newer versions of PHP are both faster and more secure, so updating will have a positive effect on your site&#8217;s performance.' ); ?></p>

	<p class="button-container">
		<?php
		printf(
			'<a class="button button-primary" href="%1$s" target="_blank" rel="noopener noreferrer">%2$s <span class="screen-reader-text">%3$s</span><span aria-hidden="true" class="dashicons dashicons-external"></span></a>',
			esc_url( wp_get_update_php_url() ),
			__( 'Learn more about updating PHP' ),
			/* translators: Accessibility text. */
			__( '(opens in a new tab)' )
		);
		?>
	</p>
	<?php

	wp_update_php_annotation();
	wp_direct_php_update_button();
}

/**
 * Adds an additional class to the PHP nag if the current version is insecure.
 *
 * @since 5.1.0
 *
 * @param array $classes Metabox classes.
 * @return array Modified metabox classes.
 */
function dashboard_php_nag_class( $classes ) {
	$response = wp_check_php_version();

	if ( $response && isset( $response['is_secure'] ) && ! $response['is_secure'] ) {
		$classes[] = 'php-insecure';
	}

	return $classes;
}

/**
 * Empty function usable by plugins to output empty dashboard widget (to be populated later by JS).
 */
function wp_dashboard_empty() {}

/**
 * Displays a welcome panel to introduce users to WordPress.
 *
 * @since 3.3.0
 */
function wp_welcome_panel() {
	?>
	<div class="welcome-panel-content">
	<h2><?php _e( 'Welcome to WordPress!' ); ?></h2>
	<p class="about-description"><?php _e( 'We&#8217;ve assembled some links to get you started:' ); ?></p>
	<div class="welcome-panel-column-container">
	<div class="welcome-panel-column">
		<?php if ( current_user_can( 'customize' ) ) : ?>
			<h3><?php _e( 'Get Started' ); ?></h3>
			<a class="button button-primary button-hero load-customize hide-if-no-customize" href="<?php echo wp_customize_url(); ?>"><?php _e( 'Customize Your Site' ); ?></a>
		<?php endif; ?>
		<a class="button button-primary button-hero hide-if-customize" href="<?php echo admin_url( 'themes.php' ); ?>"><?php _e( 'Customize Your Site' ); ?></a>
		<?php if ( current_user_can( 'install_themes' ) || ( current_user_can( 'switch_themes' ) && count( wp_get_themes( array( 'allowed' => true ) ) ) > 1 ) ) : ?>
			<?php $themes_link = current_user_can( 'customize' ) ? add_query_arg( 'autofocus[panel]', 'themes', admin_url( 'customize.php' ) ) : admin_url( 'themes.php' ); ?>